[TRAFODION-2478] Reduce the number of memory monitoring threads in Trafodion SQL processes

• Type: Improvement
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: any
• Fix Version/s: 2.1-incubating
• Component/s: sql-exe
• Assignee: Selvaganesan Govindarajan
• Reporter: Selvaganesan Govindarajan
• Created: 10/Feb/17 20:28
• Updated: 23/May/17 17:47
• Resolved: 20/Feb/17 16:44

Description

A memory monitor thread is created in every SQL process to handle the memory pressure in BMO (Big memory operators). This has following drawbacks:

1) No consistent view of the memory pressure in the node
2) Overhead of calculating the memory pressure in every trafodion SQL process.

Proposal is to move this thread to RMS SSCP process. All SQL processes have access to RMS shared segment. Hence SQL processes can get the view of the memory pressure readily and easily from the shared segment.

It is also possible to increase the frequency of the memory pressure calculation to get near real tiime picture of the memory pressure.

Issue Links

• links to: GitHub Pull Request #953